Land Rover Discovery Owners & Service Manuals

Land Rover Discovery: Interior Lighting

The interior lamp operation is activated by any of the following input signals:

  • Front and rear door latches - door ajar switch contacts
  • Tailgate latch assembly - tailgate ajar switch contacts
  • Power Mode 4 - accessory/vehicle unlocked
  • Central Door Locking (CDL) - lock request
  • Central Door Locking CDL - smart key unlock request
  • Crash sensor input from Restraints Control Module (RCM)
  • Front interior lamp switch.

The luggage compartment lamp is not switched on with the interior lamps.

This lamp is only activated when the tailgate is opened. When the tailgate is opened, the interior lamps, in addition to the luggage compartment lamps, are switched on and are subject to the CJB timers. The tailgate open signal to the CJB is provided by a tailgate ajar switch in the tailgate latch assembly.


The automatic control of the interior lamps has several switch on and off conditions as follows:

  • The interior lamps are switched on when one or more doors are opened.

    When all the doors are closed, the interior lamps are switched off after a delay of 60 seconds. If the vehicle is locked after closing the doors, within the 60 second period, the lamps go off immediately.

  • When the interior lamps are on and the ignition is in power mode 0 or 6, the lamps go off immediately after all doors have been closed.
  • In power mode 0, the interior lamps are switched on for 60 seconds. This timer is overridden if a door is subsequently opened.
  • When the vehicle is unlocked and the doors are closed, the interior lamps can be activated for a further 60 second period by pressing the 'unlock' button on the smart key.
  • When the vehicle is unlocked from a locked condition, the interior lamps are activated for a 60 second period. This timer is overridden if a door is subsequently opened.
  • If a door is left open, the interior lamps will remain on for 16 minutes.

    After this period, the CJB timer switches opens the contacts of the power saver relay and the interior lamps are switched to off to prevent excessive primary battery drain.

The CJB uses a Pulse Width Modulation (PWM) operation of the interior lamps for the on/off conditions. The lamps are switched on increasing to full intensity after a period of 1.3 seconds. The lamps are switched off with a decreasing intensity over a period of 2.6 seconds. The fade on/off operation is controlled by the CJB.


The interior lamps can be switched on or off using the manual switch for the front interior lamp. The front interior lamp switch will switch all front and rear interior lamps on or off. If the interior lamps are on when the switch is pressed, all interior lamps will go off. The on and off automatic switching conditions remain effective even when the manual switch is used.

In power mode 4 or 6 and the front interior lamp switch is used to switch the interior lamps on, the lamps will remain on continuously. If the ignition is put into power mode 0, the interior lamps will be subject to the 16 minute CJB timer. The interior lamp is immediately switched off when the vehicle is locked. After a locking procedure, the interior lamp automatic control is reinstated.


To prevent drain on the primary battery if the doors are to remain open for some time, the interior lamps can be turned off permanently. This is stored in the CJB and is also activated following a system power down or a reset of the CJB To enter the continuous off condition, the front interior lamp switch must be pressed and held for more than 2 seconds. The continuous off function can only be exited by pressing the front interior lamp switch for a further 2 seconds, after which, full automatic control is resumed. When continuous off is active, the rear interior lamp switches can still be used to switch the rear interior lamps only on or off.


The CJB receives a crash signal on a hardwired connection from the Restraints Control Module (RCM) in the event of a crash of a severity to activate the airbags. On receipt of this signal, the CJB activates the interior lamps which are on permanently and not subject to the CJB timer.

The crash operation of the interior lamps can only be cancelled by operating the switch on the front interior lamp or by locking and unlocking the vehicle.


The ambience lighting system has variable colour options which can be adjusted by the customer using a menu option in the Touch Screen (TS).

The ambience lighting system uses phosphor blue and red LED's which are combined together to make a range of five different colours from pure blue, through purple, to pure red. In addition to the colour of the ambient lighting, customers can also vary the brightness.

Automatic colour changes are also activated when the driver selects dynamic mode; the ambience lighting automatically changes from the default blue colour to red (this colour change is also repeated in the instrument cluster graphics).


Diagnostics for the interior lamps is limited to a check of the function of the front interior lamp switch. The CJB can be interrogated using a Land Rover approved diagnostic system to establish the correct operation of the front interior lamp switch, the door ajar switches and the tailgate ajar switch.



A = Hardwired; AL = Pulse Width Modulation (PWM); AN = high speed CAN powertrain systems bus; AO = high speed CAN body systems bus;


  1. Central Junction Box (CJB)
  2. Keyless Vehicle Module (KVM)
  3. Driver Door Module (DDM)
  4. Passenger Door Module (PDM)
  5. Touch Screen (TS)
  6. Interior lamp and reading lamps
  7. Footwell lamps
  8. Treadplate Light Emitting Diodes (LEDs)
  9. Instrument panel ambience lighting
  10. Door ambience lighting LEDs (4 off)
  11. Door pocket ambience lighting LED (4 off)
  12. Door handle ambience lighting LED (4 off)
  13. Luggage compartment ambience lighting LEDs
  14. Rear interior lamps
  15. Glovebox switch and lamp assembly
  16. Luggage compartment lamp
  17. Ground
  18. Power supply from Battery Junction Box (BJB)
  19. Passenger door latch - ajar switch
  20. Left rear door latch - ajar switch
  21. Right rear door latch - ajar switch
  22. Driver door latch - ajar switch
  23. Tailgate latch - ajar switch
  24. Front interior lamp and reading lamps - overhead console
  25. Lighting control switch
  26. Stop/start switch
  27. Restraints Control Module (RCM) - crash signal


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